[ET-VK] Fix force_fp16 texture bias being silently rejected for CONTIGUOUS_ANY ops

[SS-JIA]

Stack from ghstack (oldest at bottom):

• [ET-VK] Fused RMSNorm operator to fix fp16 overflow #18772
• [ET-VK] Deduplicate transition clone nodes in TagMemoryMetaPass #18771
• -> [ET-VK] Fix force_fp16 texture bias being silently rejected for CONTIGUOUS_ANY ops #18770

The force_fp16 path in TagMemoryMetaPass applies ANY_TEXTURE to
bias ops toward texture storage. However, try_constrain_with_arg_repset
has a packed-dim compatibility check that requires ALL of the source
repset's PDIs to exist in the output repset. ANY_TEXTURE has 3 texture
layouts (WP, HP, CP) but CONTIGUOUS_ANY outputs only support WP, so
the check fails and the texture bias is silently dropped.

Without the bias, buffer storage cascades from ops that must use buffer
(e.g. embedding with vocab exceeding texture limits) into downstream ops
that could use texture, causing unnecessary buffer↔texture transitions.

Fix: check PDI compatibility against the intersection of arg and source
repsets (what would actually be applied) rather than the raw source. The
intersection of ANY_TEXTURE ∩ CONTIGUOUS_ANY = WIDTH_PACKED_TEXTURE,
which IS compatible with the output.

Authored by Claude.

Differential Revision: D100004702

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